From: Andi Kleen <ak@suse.de>
Date: Wed, 11 Jan 2006 21:44:57 +0000 (+0100)
Subject: [PATCH] x86_64: Make the cpu_*_maps in kernel/sched.c read mostly
X-Git-Tag: v2.6.16-rc1~329
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4cef0c61380888af99b054937ed391fb28757836;p=linux-2.6

[PATCH] x86_64: Make the cpu_*_maps in kernel/sched.c read mostly

They are referred to often so avoid potential false sharing for them.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/kernel/sched.c b/kernel/sched.c
index d129e560cc..c0c60c926d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3980,12 +3980,12 @@ asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len,
  * method, such as ACPI for e.g.
  */
 
-cpumask_t cpu_present_map;
+cpumask_t cpu_present_map __read_mostly;
 EXPORT_SYMBOL(cpu_present_map);
 
 #ifndef CONFIG_SMP
-cpumask_t cpu_online_map = CPU_MASK_ALL;
-cpumask_t cpu_possible_map = CPU_MASK_ALL;
+cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL;
+cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL;
 #endif
 
 long sched_getaffinity(pid_t pid, cpumask_t *mask)